Submersible float control



March 29, 1960 F. M. NASH 2,930,867

SUBMERSIBLE FLOAT CONTROL Filed July 24, 1957 s Sheets-Sheet 1 f/GL. I22

INVENTOR. FLOYD M. NASH BYZ7A4/PL A T TORNEVS March 29, 1960 F. M. NASH 2,930,867

SUBMERSIBLE FLOAT CONTROL Filed July 24, 1957 3 Sheets-Sheet 2 INVENTOR. FLOYD M. NASH A 7' TO/PNEYS 3 Sheets-Sheet 3 Filed July 24, 1957 I I I I I I l l l I INVENTOR. FLOYD M NASH A T TORNE VS UnitedStates Pat nt 0."

This invention relates to pump systems and particularly to submersible pump installations and the construction and sealing thereof.

Submersible pump installations are widely used for a variety of applications such as sump pumps, hydromassage units and others.

An object of the present invention is to provide a novel and improved float or floats operating a switch in connection with a submersible pump.

Another object of this invention is to provide such a float or floats which will present no appendages beyond the outer motor shell.

A further object of this invention is to provide a connection between the switch sealed in the motor housing and the outside means of control without impairing the seal of said housing.

Yet another object of the invention is to provide a switch incorporated in the float or floats system which will eliminate the need for means for mechanically transmitting the float movement to the sealed-in switch.

Still a further object of the invention is to provide a float system which will allow a sufiicient switch actuating liquid level diflferential necessary for the operation of a sump pump.

Figure 1 is a view in perspective of a submersible pump with part of the housing cut away to show the sectionalized motor with its connections and its automatic switch control mechanism.

Figure 2 is a vertical sectional view of the lower part of the pump housing shown in Figure 1, illustrating the operation of the float and the switch connected thereto.

Figure 3 is a plan sectional view through Figure 2 on the line 3-3.

Figure 4 is a vertical sectional view of the lower part of the pump housing shown in Figure 1, with a mercury switch embodied in the float replacing the sealed-in switch of Figure l. I

Figure 5 is a plan sectional view through Figure 4 on the line 55.

Figure 6 is a vertical, sectional view through a sump pump housing in which the float shown on the previous drawings is supplemented with a second higher positioned float and a vertical rod connected thereto, the common action of both floats serving to increase the switch actuating liquid level differential of the pump.

Referring to the drawings in detail, Figure 1 shows a submersible pump and motor unit, with impeller housing 10 and impeller shaft 12 driven by motor 14. Ports 16 serve as liquid inlet means into the impeller housing and duct 18, shown in a sectionalized condition, provides the outlet means. Motor 14 is encased in an outer shell comprising cylindrical lateral wall 20, cap 22, and bottom plate 24 and an inner shell which is hermetically sealed and comprises lateral wall 26, top plate 28 and bottom plate 30. An extension of bottom plate 30 provides a separate enclosure 32 for switch box 34 and button 36. The space delimited by plates 24 and 30 and wall serves as a float chamber enclosing switch 2,930,867 Patented Mar. 29, 1960 'Reference is made to Figure 3 for a detailed description of the switch control means. Ports 41 serve as liquid inlet means into the float chamber.

Figure 2 represents float 38 in two extreme positions and actuating switch button control mechanism depicted in Figure 3.

Figure 3 shows arcuate float 38, float arm 40 fixedly connected to shaft 42 by means of nut 44 and tight connected sleeve 46. Shaft 42 penetrates enclosure 32 through guide sleeve 48 which is in threaded and sealed engagement with the wall of enclosure 32. The O-ring seal 50 is made to press against shaft 42 by means of plug 52 which is in threaded engagement with guide sleeve 48. Cam 54 is in fixed connection with shaft 42. Rubber tube 56 provides a flexible connection and maintains a clearance space between sleeves 46 and 48. Removable clamps 58 and 60 keep tube 56 in sealed connection with sleeves 46 and 48.

Motor 14 is normally shut off when float 38 is down, i.e. when cam 54 yieldingly maintains switch button 36 in its upper position. As soon as the liquid level rises and enters the float chamber, the buoyancy of float 38 causes it to rise also. The resulting rotational movement imparted to shaft 42 against the torsional resistance of flexible rubber tube 56 causes cam 54 to swing downwardly, enabling downward movement of the springurged switch button 36 and the consequent starting of motor 14.

Reversely, the falling liquid level will lower float 38 to the point where cam 54 again actuates switch button 36, shutting ofl motor 14.

The automatic float switch control mechanism in Figure 4 does not require means for mechanically transmitting the float movement to a sealed-in switch. Float 62 embodies a mercury switch 66 provided with leads 68 and 70 connecting it to motor 14 by means comprising float extension 64, conduit 72 in threaded and sealed engagement with plate 30, and interconnecting rubber tube 74 which maintains said extension and said conduit in spaced relation, thereby enabling pivotal movement of float 62. Clamps 76 and 78 keep the rubber tube in sealed connection with extension 64 and conduit 72.

Figure 5 is a plan sectional view of the mechanism shown in Figure 4.

Figure 6 shows a sump pump motor housing, analogous tothe motor housing set forth in Figure 1. Numerals pertaining to the housing of Figure 6 are the same as the corresponding numerals in Figure 1, preceded by numeral 1.

Float 80, in Figure 6, and the switch control mechanism actuated thereby corresponds to that of Figure 1. Float 80 supplemented by a second float 82, located between cap 122 and plate 128. Extension 84 of float 82 is connected to vertical rod 86 which is slidably disposed between walls and 126. Said rod extends into the float chamber containing float 80.

Float 80, rising with the liquid level, engages the rod end 88 before the float reaches switch-actuating position. Float 80 lacks sufiicient buoyancy to raise the dead weight consisting of float 82 and rod 86, and therefore the liquid level must rise to the level of float 82 and raise float 82 and rod 86 before float 80 is able to complete its travel and actuate the switch. As the liquid level is lowered by the pump to below the level of float 82, the dead weight of float 82 and rod 86 is not suflicient to depress float 80 to the solid line, or motor-de-energizing, position shown in Figure 6. Consequently, the pump will continue to operate until the liquid level drops sufliciently to enable float 80 to return to said solid line position. The mechanism set forth in Figure 6 allows It will be appreciated that the reason why the switches are not reversely actuated immediately upon downward movement of the floats (38, 62 and 80) is, in the instance of floats 38 and 80, that the switch buttons 36, just like the toggle buttons of the conventional wall-located light switches, travel a material degree in each direction of movement until the over-center, or switch actuating, position is reached, and is, in the instance of float 62, due to the inertia of the mercury in the switch.

What is claimed is:

A sump pump float switch control;comprising at least a pair of interacting floats disposed in spaced relation one above the other, a switch, switch actuating means therefor connected to the lower float, a vertically and slidably disposed rod attached to the upper 'float and level falls below said upper float, whereby said switch is actuated in said one direction in response to flotation movement upwardly of said upper float and is reversely actuated in response to flotation movement downwardly of said lower float.

References Cited in the file of this patent UNITED STATES PATENTS.

842,554 Johnson Jan. 29, 1907 1,090,497 Patterson Mar. 17, 1 91 r 1,392,652 Muzzy Oct. 4, 1921 2,043,530 Dezotell June 9, 1936 2,076,547 Carlson ;;.Apr. 13, 1937 2,136,220 Shepherd Nov. 8, 1938 2,377,330 Dixon June 5, 1945 2,467,189 Cohen et al. Apr. 12, 1949 2,580,759 Gille Jan. 1, 1952 2,796,884 Jones June 25, 1957 FOREIGN PATENTS 2,277 Great Britain Jan. 29, 1904 103,453 Australia Mar. 10, 1938 

